2-Methylpyrazine

Description

2-Methylpyrazine has an odor threshold in water variously reported at 60,000 or 105,000 ppb. May be prepared from the corresponding carboxylic acid; by catalytic dehydrogenation of 2-methyl-piperazine; by condensation of methylglyoxal with ethylenediamine.

Chemical properties

clear colorless to slightly yellow liquid

Chemical properties

2-Methylpyrazine has a nutty, cocoa, green, roasted, chocolate, meaty odor.

Occurrence

Reported found in bakery products, roasted barley, cocoa products, coffee, dairy products, cooked meats, peanuts, filberts, pecans, popcorn, potato chips, rum and whiskey, soy product, roasted filberts, roasted almonds, guava, papaya, asparagus, kohlrabi, baked and fried potato, milk, boiled egg, smoked fish, beer, coffee, sesame seed, rice, sukiyaki, buckwheat, sweet corn, corn tortillas, malt, wort, wild rice, okra, crayfish, clam, squid and maté.

The Uses of 2-Methylpyrazine

2-Methylpyrazine is used as flavoring agents in bread fresh bread, butter, chocolate, chocolate cocoa, coffee, meat roasted, nut almond.

The Uses of 2-Methylpyrazine

These Secondary Standards are qualified as Certified Reference Materials. These are suitable for use in several analytical applications including but not limited to pharma release testing, pharma method development for qualitative and quantitative analyses, food and beverage quality control testing, and other calibration requirements.

Preparation

From corresponding carboxylic acid; by catalytic dehydrogenation of 2-methyl-piperazine; by condensation of methylglyoxal with ethylenediamine

Definition

ChEBI: Methylpyrazine is a member of the class of pyrazines that is pyrazine in which one of the hydrogens is replaced by a methyl group. It is a flavouring agent found in coffee, peanuts and red peppers. It has a role as a flavouring agent, a plant metabolite and a Maillard reaction product.

Aroma threshold values

Detection: 60 ppb to 100 ppm

Taste threshold values

Taste characteristics at 75 ppm: nutty, brown, musty, roasted and astringent

General Description

2-Methylpyrazine is an alkyl-substituted pyrazine used as a key intermediate in the synthesis of pyrazineamide, an anti-tubercular drug.

Safety Profile

Moderately toxic by ingestion and intraperitoneal routes. Mutation data reported. Flammable liquid when exposed to heat, sparks, or flame. Can react with oxidizing materials. To fight fire, use water spray, foam, dry chemical, CO2. When heated to decomposition it emits highly toxic fumes of NOx.

Purification Methods

Purify it via the picrate and distil the free base. The picrate has m133-134o(from EtOH). [Wiggins & Wise J Chem Soc 4780 1956, Beilstein 23 III/IV 911, 23/5 V 386.]